As Symbol as That: Inconsistencies in Symbol Systems of Alleles in Textbooks, and Students’ Justifications for Them

In genetics education, symbols are used for alleles to visualize them and to explain probabilities of progeny and inheritance paradigms. In this study, we identified symbol systems used in genetics textbooks and the justifications provided for changes in the symbol systems. Moreover, we wanted to understand how students justify the use of different symbol systems when solving genetics problems. We analyzed eight textbooks from three different countries worldwide. We then presented a genetics problem to eight 9th-grade students and probed their justifications for the use of different symbol systems. Our findings showed that there is no one conventional symbol system in textbooks; instead, symbol systems are altered along and within textbooks according to the genetic context. More importantly, this alteration is not accompanied by any explicit explanation for the alteration. Student interviews revealed that some students were able to identify the genetic context of each symbol system, whereas others, who were unable to do so, provided justifications based on different non-genetics-related reasons. We discuss the implications of our analysis for how multiple symbol systems should be presented in textbooks, and how they should be introduced in the classroom.

Keeping Track with Things

The chapter begins with an evolutionary account of tracking systems, from simple detection systems to complex decoupled and highly flexible tracking systems. The important mediator is the role of the environment in providing the complexity, translucency, and hostility that produces the evolutionary pressures that result in more complex tracking systems. An evolutionary platform is provided for how modern humans could have come to innovate epistemic tracking tools (ETTs) for keeping track of salient features of the environment. Three examples of ETTs in action are given, ranging from highly iconic and contextual learning tools—such as the Mattang—to highly abstract and decoupled conventional symbol systems. Finally, it is argued that ETTs are compatible with a responsibilist-reliabilism since their correct deployment requires epistemic diligence and the reliable functioning of the tool itself. As such, a framework for understanding and exploring how we keep track with things has been given.

Algebra

The difference between the transcendent Coleridgean symbol and the unreliable conventional symbol was of explicit concern in Victorian mathematics, where the former was aligned with Euclidean geometry and the latter with algebra. Rather than trying to bridge this divide, practitioners of modern algebra and the pioneers of symbolic logic made it the founding principle of their work. Regarding the content of claims as a matter of “indifference,” they concerned themselves solely with the formal interrelations of the symbolic systems devised to represent those claims. In its celebration of artificial algorithmic structures, symbolic logician Lewis Carroll’s Sylvie and Bruno dramatizes the power of this new formalist ideal not only to revitalize the moribund field of Aristotelian logic but also to redeem symbolism itself, conceived by Carroll and his mathematical, philosophical, and symbolist contemporaries as a set of harmonious associative networks rather than singular organic correspondences.

A DATA PARALLEL PROBLEM SOLVING ARCHITECTURE FOR THE RECONSTRUCTION OF PHYSICAL EVENTS

A system is presented which is able to reconstruct the physical processes after the annihilation of particles in collider rings like LEP. It can be shown that the reconstruction task belongs to the class of NP-complete problems. Neither the conventional symbol processing approach of artificial intelligence nor connectionist systems alone satisfy the requirements of the application. A hybrid system is introduced in which a genetic algorithm acts together with a model-based hillclimbing component. The power of this method is based on the interaction of a dynamically and an inferentially working module. The inherent parallelism of dynamic systems makes a implementation on a parallel architecture useful. A data parallel implementation of this algorithm on the Connection Machine Model CM-2 is described. At last the reconstruction system is applied to a classification task, the identification of the initial quark pair. The results are compared with a conventional analysis method and a neural network.

Ritualized gesture and expression in art

I hope I may dispense with the ritual of an introduction and plunge in medias res with the aid of my first illustration, an anti-war poster of 1924 by the German expressionist artist Kaethe Kollwitz (figure 1, plate 14). It shows the various aspects of gesture and expression I should like to single out for discussion. The young man on the poster surely exhibits those symptoms of mass emotion that Konrad Lorenz has recently analysed so convincingly in the penultimate chapter of his book on aggression (Lorenz 1963), the heightened tonus, the rigid posture, the raised head with the forward thrust of the chin, even the bristling hair, all the physical reactions that accompany the emotion of mass enthusiasm or Begeisterung . If we retain the term symptom for these visible signs the artist has here represented, we may use the term symbol for the other kind of visible sign, the gesture of the hand with its two outstretched fingers which conventionally accompanies the swearing of an oath in central Europe, a ritual in the narrow cultural sense of the term. If natural symptom and conventional symbol can be seen as the two extremes of a spectrum (Gombrich 1963 b ) we would, I believe, have to place the gesture the young man performs with his left hand somewhere in between these extremes.

The Society’s Emblem

The Emblem of the Society shall depict two concentric circles with the words "The Society of Naval Architects and Marine Engineers" between the circles, with the space inside the circles so designated as to depict the conventional symbol for the midship section of a ship, all as below. (Article III.)